AD NUMBER: 2009-12-51

SUMMARY: This emergency AD results from reports
of oil leaks from certain reduction gearbox (module M05) front
casings. The engine manufacturer reported that the lubrication duct
plug was not properly bonded/ glued in place. This condition, if
not corrected, could result in loss of the lubrication duct plug,
followed by a rapid draining of the oil tank, without indication to
the cockpit through low oil pressure warning. This condition can
lead to uncommanded in-flight engine shutdown, possible engine
fire, and an emergency autorotation landing.

We have identified an unsafe condition that is likely to exist
or develop on other Turbomeca S.A. Arriel turboshaft engines of
this same type design. This AD requires initial and repetitive
visual inspections of affected modules M05 for oil leakage, repair
if leaking, and repair of all affected modules as terminating
action to the repetitive inspections. You must use the service
information described previously to perform these actions.